Rock-drill valve



Nov. 16 1926- c. c. HANSEN ROCK DRILL VALVE Filed May 27, 1925 INVENTOR ples CImwcn H/S' ATTOREY Patented Nov. 15, 1926.

UNITED STATES 1,696,835 PATENT OFFICE.

CHARLES C. HANSEN, OF EASTON, ENNSYLVANIA, ASSIGNCR TO NGERSOLi-RAND COMPANY, 0F JERSEY CITY, NEWv JERSEY, A CORP'GRATION OF'NEW' JERSEY.

ROCK-DRILL VALVE.

Application led May 27, 1925. Serial No. 33,105.

This invention relates to fluid actuated rock drills, but more particularly to an improved valve and valve construction which may be conveniently located rearwardly of the cylinder.

The objects of the invention are to secure a valve construction in which the distributing valve for the rock drill may surround the water tube `of the machine and slide transversely relatively to said` water tube. .ln a machine in which automatic rifle bar rotation is provided for the drill'steel the valve will preferably be located rearwardly of the rotation head andv ratchet ring so that the valve is readily accessible and the valve construction does not materially increase the length of the machine.

Further objects will hereinafter appear and the invention is shown in one of its preferred forms in the accompanying drawings, in which Figure l is a longitudinal sectional elevation of so much of a rock drill as will serve to illustrate the invention,

Figure 2 is a similar view with the pis- .tion and valve in a different position,

Figure 3 is a transverse sectional plan view on the line 8-3 of Figure l looking in the direction of the arrows, and

Figure 4 is a detail side elevation of the valve.

Referring to the drawings, the cylinder A is provided with the reciprocating piston B having the fluted forward extension or shank C. The usual rifle bar D cooperates with the piston. The cylinder is provided with a free exhaust E located centrally of the ends of the cylinder and controlled only by the piston. The usual water tube F eX- tends through the rifle bar D and piston B andthe pressure fluid supply of the machine is controlled by the throttle v-alve G in the back head H. Between theback head H and the back cylinder head block .l is arranged a head plate K and the valve L is located in the valve chamber O, in this instance located within the back head H.

The valve L is'in the form ofa rectangular slidable block having a hollow central portion P surrounding the water tube F with sufficient clearance to permit the block to slide back and forth. A sleeve Q is preferably provided over a portion of the water tube F and is seated in the back head H and plate K in order to form a tight connection.

A member or members R constituting a valve box within the back head also forms stops for the valve to llimit its travel and passages S in said valve boX connect the valve chamber O with the inlet passages T and U leading respectively to the cylinder,

inlet ports V and lV at opposite ends of the cylinder.

The valve L is of the current thrown type i and controls only the inlet passages and ports to the ends of the cylinder. The valve as shown is of an appreciably greater length than width or height, and the longer sides form seating surfaces of the valve alternately exposed to reduced pressure in the cylinto close the Vvalve at the side from which the pressure is reduced in the operation of the piston. The lianges X are preferably located slightly inwardly from the sides of the valve to form opposed symmetrical pressure areas X onsaid flanges and which pressure areas are constantly exposed to pressure fluid from the source'of supply for throwing the valve.

In the operation of the device let it be assumed that the piston, as shown in Figure l, is starting to travel on its forward stroke and the valve is in the position indicated in said figure. In such case pressure fluid is supplied at the throttle G which should be open passes to the valve chamber O and thence through the recesses Y in both flanges at one side of the valve to the inlet port V at the rear end of the cylinder to drive the piston forwardly. After the piston has passed and uncovered the exhaust port'E there willbe a considerable drop in pressure rearwardly of the piston. As a result, the pressure fluid flowing over the side of the valve will create a suction tending to move the valve to the right as Figure l is viewed.

As hereinbefore stated, the pressure areas 'Y sist the suction oi the pressure fluid flowing over the other side of the valve to throw the valve in the direction of the supply passage S. After the piston covers the free exhaust port l), the air entrapped in the front end ot the cylinder will be compressed and such compressed air may then also assist the other 'forces in actuating the valve. However, the

" action of the valve is not dependent upon the air compressed by the piston. The suclring action exerted by the pressure fluid. iii iowing over the valve and the pressure fluid acting against the pressure areas X being suiiicient to throw the valve.

In Figure 2 the piston is shown substantially at the end of its forward stroke ready to return on its rearward stroke and the valve is indicated as having moved to its opposite position to admit live pressure iiuid to the forward end ofthe cylinder through the cylinder inlet port lV. From this point in the operation of the devicel the cycle is repeated. y Y.

One ot' the advantages of this valve construction resides in the fact that the seating surfaces oi' the valve are longer than the seating surfaces oi' a round or spool valve having substantially the saine surface area subject to pressure and in consequence the valve of the present invention 'may have thel minimum travel for a given valve opening.

I clarin:

l. A fluid actuated rock drill, comprising a cylinderand reciprocating piston, a water tube extending through the piston, a free exhaust port located centrally of the eylinder and controlled only by the piston, a fluid distriliuting valve in the forni of a rectangular slidable block located rearwardly ontV the cylinder around the water tube, opposed pressure areas on the sides of the valve constantly exposedto pressure iiuid for throwing the valve, and inlet ports for the ends a fluid distributing valve in the form of av rectangular slidable block located rearwardlyA otiftheY cylinder around the water tube, said valve having a central aperture through which the `water tube extends, op-

a. cylinder and reciprocating piston, a water i tube extending through the piston, a free exhaust port located centrally of' the cylinder and controlled only by the piston, a valve box located rearwardly of the cylinder and having a rectangular valve chamber, a distributing valve .in said box in the Vi'oriii of a rectangular slidable block having an open central portion encircling the water tube, opposed syn'in'ietrical pressure areas on the sides of' the valve constantly exposed to pressure fluid for throwing the valve, and inlet ports for the ends of the cylinder rontrolled only by said valve.

Ll. A fluidactuated rock drill, comprising a cylinder and reciprocating piston, a water tube extending through the piston, a free exhaust port located centrally of the cyliiidei' and controlled only by the piston, a valve box located rearwardly of the cylinder and having a rectangular valve chamber, a distributing valve in said box in the forni ot' a rectangular slidable block having an open central portion encircling the water tube, said valve being reciprocable in a plane extending transversely through the water tube and of appreciably greater length than width, and the longer sides forming the surfaces of the valve alternately exposed to reduced pressure, and inlet portsfor the ends of the cylinder controlled only by said valve. y

around the water tube,ia freeA exhaust port located centrally of the cylinder Aand controlled only by the piston, a fluid distributing valve in the form of arectangular block. located rearwardly of the cylinder `around the water tube sleeve, said valve being reciprocable lin a plane extending transversely through the sleeve, and inlet ports for the ends of the cylinder controlled only by said valve.

In testimony whereof l have signed this specification.

CHARLES o. HANSEN. 

